Enhancement of antibacterial activity in CuO/ZnO nanohybrid p-n heterojunctions

The p-n heterojunctions may contribute to the antibacterial effect, but the study on this issue is limited and the interpretation remains controversial. Herein, we designed p-n heterojunctions in CuO/ZnO nano-hybrids, demonstrating remarkable antibacterial efficiency against Escherichia coli (Gram negative) of 93.94 % and Staphylococcus aureus (Gram positive) of 95.69 % at an ultra-low concentration of 10 μg/ml. Mott-Schottky analysis reveals the formation of p-n heterojunctions at CuO/ZnO interfaces, elevating the generation of reactive oxygen species, which is responsible for the enhanced antibacterial behaviors. The CuO/ZnO nano-hybrids with p-n heterojunctions are expected to be a high-efficient, broad-spectrum antibacterial materials for practical applications.